When a viewer is viewing an object, the viewer often goes ahead one or more steps or tilts his/her body forward to view some details more clearly since such details are small. Similarly, when the viewer is watching a movie or a television program, the viewer may also tilt his/her body forward or moves forward by a certain distance when some objects are displayed on a display screen and the viewer intends to view the objects more clearly. However, some details cannot be viewed clearly even if the viewer moves forward by the certain distance or tilts his/her body forward, since the details are too small or a definition of the displayed picture is too low.
In existing displaying technologies, no matter in a 2D display or in a 3D display technology, when the viewer moves forward by the certain distance or tilts his/her body forward, there is not an interaction function for enlarging details desired by the viewer, thus ambience of the viewer being weak.